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Genetic influence

Posted: Thu Sep 19, 2019 11:09 am
by LJCB
I recently saw a post talking about what a bull is really worth on Facebook and he said a lot of things but one thing stuck out that I didn’t quite get or I didn’t agree with.

The post said that a cow only has 5% genetic influence of that years calves and the bull has 50%.

I agree changing your bull can change your genetics a lot but If I’m wrong correct me I don’t get how a cow can only influence a calf by 5%.

Re: Genetic influence

Posted: Thu Sep 19, 2019 11:36 am
by Ky hills
LJCB wrote:
Thu Sep 19, 2019 11:09 am
I recently saw a post talking about what a bull is really worth on Facebook and he said a lot of things but one thing stuck out that I didn’t quite get or I didn’t agree with.

The post said that a cow only has 5% genetic influence of that years calves and the bull has 50%.

I agree changing your bull can change your genetics a lot but If I’m wrong correct me I don’t get how a cow can only influence a calf by 5%.
I'm no geneticist, but I don't agree with that assessment either in the context of each cow and their individual calves. Maybe if one was saying the total effect on the entire herd overall then one cow would be a less percentage and the bull would be 50%, which may have been the intended context.
If that were true for an individual cow, then it would undermine the concept of a superior cow. Logic would say that some cows are better quality than others.

Re: Genetic influence

Posted: Thu Sep 19, 2019 12:25 pm
by Son of Butch
LJCB wrote:
Thu Sep 19, 2019 11:09 am
I recently saw a post talking about what a bull is really worth on Facebook....
The post said that a cow only has 5% genetic influence of that years calves and the bull has 50%.
Congratulations LJ

I believe you have found who should be our candidate for "Bull Salesman Of The Year."

Twisting facts to justify a bull's price... B.S. doesn't get much deeper than that... or does it?

Re: Genetic influence

Posted: Thu Sep 19, 2019 12:37 pm
by Logan52
I think what the facebook post was referring to is that the bull contributes 50% of the total herd genetics over time. With roughly 20 cows for every bull, any individual cow only contributes about 5% to the total genetics as compared to the bull, (or something like that).
Thus, you can improve improve herd genetics more easily through the bulls you use than through the cows you keep.

I believe in the importance of cow families and that the influence of a good cow through her progeny over the generations is greater than what this implies.

Re: Genetic influence

Posted: Thu Sep 19, 2019 12:43 pm
by Ky hills
Son of Butch wrote:
Thu Sep 19, 2019 12:25 pm
LJCB wrote:
Thu Sep 19, 2019 11:09 am
I recently saw a post talking about what a bull is really worth on Facebook....
The post said that a cow only has 5% genetic influence of that years calves and the bull has 50%.
Congratulations LJ

I believe you have found who should be our candidate for "Bull Salesman Of The Year."

Twisting facts to justify a bull's price... B.S. doesn't get much deeper than that... or does it?
Wonder if they'll change the story when trying to sell heifers or cows? If not it might make it hard to sell them real good ones for a premium price, being as how they don't contribute much genetic influence.

Re: Genetic influence

Posted: Thu Sep 19, 2019 6:31 pm
by Jeanne - Simme Valley
yes, that is the "normal" blah-blah about the contributing factor of a bull. It is somewhat true, but like Logan says, cow families can have more of an impact than that 5% quote (based on 20 cow herd for 1 bull).

Re: Genetic influence

Posted: Thu Sep 19, 2019 6:44 pm
by wbvs58
Logan52 wrote:
Thu Sep 19, 2019 12:37 pm
I think what the facebook post was referring to is that the bull contributes 50% of the total herd genetics over time. With roughly 20 cows for every bull, any individual cow only contributes about 5% to the total genetics as compared to the bull, (or something like that).
Thus, you can improve improve herd genetics more easily through the bulls you use than through the cows you keep.

I believe in the importance of cow families and that the influence of a good cow through her progeny over the generations is greater than what this implies.
Yes and the influence of good cow families will inflate that 5% a lot as heifers from those good cows are more likely to be kept while the run of the mill will be culled.

Ken

Re: Genetic influence

Posted: Thu Sep 19, 2019 9:35 pm
by LJCB
Logan52 wrote:
Thu Sep 19, 2019 12:37 pm
I think what the facebook post was referring to is that the bull contributes 50% of the total herd genetics over time. With roughly 20 cows for every bull, any individual cow only contributes about 5% to the total genetics as compared to the bull, (or something like that).
Thus, you can improve improve herd genetics more easily through the bulls you use than through the cows you keep.

I believe in the importance of cow families and that the influence of a good cow through her progeny over the generations is greater than what this implies.
Makes more sense. I think I got up in the whole 5% thing and didn’t read the context of the whole thing 😂.

Re: Genetic influence

Posted: Thu Sep 19, 2019 11:37 pm
by Son of Butch
Even in the context of author's intent, it's still a double talk pile of B.S.

example:
IF cow herd is homozygous polled PP and bull horned HH = 100% polled calves and PH carriers.
Not a single calf with horns for roping.
Breed those HP calves to Homo-PP = 100% hornless with 50% back to being homo PP and 50%
PH carriers = 25% influence by the horned sire in 2nd generation.

example 2: Codominant genes ie: Shorthorns
1 parent homo red RR other parent homo white WW = 100% offspring red and white and hetero RW


50% genetic influence by bull 5% by cow = 55% What happens to the other 45% of the genes?
The guy is too big of a sack of ja-hooy to even bother dealing with.